Performance Evaluation of Reflective Crack Mitigation Techniques for Soil-Cement Bases

Abstract

The Louisiana Department of Transportation and Development (DOTD), U.S., has been using chip seal as an interlayer over cement stabilized base courses over the last several years to mitigate the reflective cracking for flexible pavements. Furthermore, DOTD is also changing the soil-cement base type from traditional cement stabilized design (CSD) to cement treated design (CTD) as another technique to control reflective cracks. There have been no large-scale studies conducted to determine the effectiveness of chip seal interlayer over CSD bases or CTD bases (without any interlayer) as a way of reflective crack control. Therefore, the focus of this study is to evaluate both these techniques by using the available time-series distress data (roughness, cracking, and rutting) in the pavement management system. With the help of this distress data, the performance of all different categories of projects was evaluated by two parameters: average service lives (SL) and benefit areas. Along with the ascertained cost, the SL and benefit areas were also used to determine benefit/cost (B/C) ratios for each category of projects. Subsequently, the cost-effectiveness of chip seal interlayer over CSD bases and CTD bases was assessed by the comparison of the B/C ratios. The performance and cost-effectiveness of few stone interlayer projects were also reported in this study. Finally, it was concluded that the chip seal interlayer is the least cost-effective option and CTD bases without any interlayer appeared to be the most cost-effective technique for reflective crack mitigation in Louisiana.